#!/usr/bin/python

# Copyright Ansible Project
# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
# SPDX-License-Identifier: GPL-3.0-or-later

from __future__ import annotations


DOCUMENTATION = r"""
module: vertica_role
short_description: Adds or removes Vertica database roles and assigns roles to them
description:
  - Adds or removes Vertica database role and, optionally, assign other roles.
extends_documentation_fragment:
  - community.general.attributes
attributes:
  check_mode:
    support: full
  diff_mode:
    support: none
options:
  role:
    description:
      - Name of the role to add or remove.
    required: true
    type: str
    aliases: ['name']
  assigned_roles:
    description:
      - Comma separated list of roles to assign to the role.
    aliases: ['assigned_role']
    type: str
  state:
    description:
      - Whether to create V(present), drop V(absent) or lock V(locked) a role.
    choices: ['present', 'absent']
    default: present
    type: str
  db:
    description:
      - Name of the Vertica database.
    type: str
  cluster:
    description:
      - Name of the Vertica cluster.
    default: localhost
    type: str
  port:
    description:
      - Vertica cluster port to connect to.
    default: '5433'
    type: str
  login_user:
    description:
      - The username used to authenticate with.
    default: dbadmin
    type: str
  login_password:
    description:
      - The password used to authenticate with.
    type: str
notes:
  - The default authentication assumes that you are either logging in as or sudo'ing to the C(dbadmin) account on the host.
  - This module uses C(pyodbc), a Python ODBC database adapter. You must ensure that C(unixODBC) and C(pyodbc) is installed
    on the host and properly configured.
  - Configuring C(unixODBC) for Vertica requires C(Driver = /opt/vertica/lib64/libverticaodbc.so) to be added to the C(Vertica)
    section of either C(/etc/odbcinst.ini) or C($HOME/.odbcinst.ini) and both C(ErrorMessagesPath = /opt/vertica/lib64) and
    C(DriverManagerEncoding = UTF-16) to be added to the C(Driver) section of either C(/etc/vertica.ini) or C($HOME/.vertica.ini).
requirements: ['unixODBC', 'pyodbc']
author: "Dariusz Owczarek (@dareko)"
"""

EXAMPLES = r"""
- name: Creating a new vertica role
  community.general.vertica_role: name=role_name db=db_name state=present

- name: Creating a new vertica role with other role assigned
  community.general.vertica_role: name=role_name assigned_role=other_role_name state=present
"""
import traceback

PYODBC_IMP_ERR = None
try:
    import pyodbc
except ImportError:
    PYODBC_IMP_ERR = traceback.format_exc()
    pyodbc_found = False
else:
    pyodbc_found = True

from ansible.module_utils.basic import AnsibleModule, missing_required_lib


class NotSupportedError(Exception):
    pass


class CannotDropError(Exception):
    pass


# module specific functions


def get_role_facts(cursor, role=""):
    facts = {}
    cursor.execute(
        """
        select r.name, r.assigned_roles
        from roles r
        where (? = '' or r.name ilike ?)
    """,
        role,
        role,
    )
    while True:
        rows = cursor.fetchmany(100)
        if not rows:
            break
        for row in rows:
            role_key = row.name.lower()
            facts[role_key] = {"name": row.name, "assigned_roles": []}
            if row.assigned_roles:
                facts[role_key]["assigned_roles"] = row.assigned_roles.replace(" ", "").split(",")
    return facts


def update_roles(role_facts, cursor, role, existing, required):
    for assigned_role in set(existing) - set(required):
        cursor.execute(f"revoke {assigned_role} from {role}")
    for assigned_role in set(required) - set(existing):
        cursor.execute(f"grant {assigned_role} to {role}")


def check(role_facts, role, assigned_roles):
    role_key = role.lower()
    if role_key not in role_facts:
        return False
    return not (assigned_roles and sorted(assigned_roles) != sorted(role_facts[role_key]["assigned_roles"]))


def present(role_facts, cursor, role, assigned_roles):
    role_key = role.lower()
    if role_key not in role_facts:
        cursor.execute(f"create role {role}")
        update_roles(role_facts, cursor, role, [], assigned_roles)
        role_facts.update(get_role_facts(cursor, role))
        return True
    else:
        changed = False
        if assigned_roles and (sorted(assigned_roles) != sorted(role_facts[role_key]["assigned_roles"])):
            update_roles(role_facts, cursor, role, role_facts[role_key]["assigned_roles"], assigned_roles)
            changed = True
        if changed:
            role_facts.update(get_role_facts(cursor, role))
        return changed


def absent(role_facts, cursor, role, assigned_roles):
    role_key = role.lower()
    if role_key in role_facts:
        update_roles(role_facts, cursor, role, role_facts[role_key]["assigned_roles"], [])
        cursor.execute(f"drop role {role_facts[role_key]['name']} cascade")
        del role_facts[role_key]
        return True
    else:
        return False


# module logic


def main():
    module = AnsibleModule(
        argument_spec=dict(
            role=dict(required=True, aliases=["name"]),
            assigned_roles=dict(aliases=["assigned_role"]),
            state=dict(default="present", choices=["absent", "present"]),
            db=dict(),
            cluster=dict(default="localhost"),
            port=dict(default="5433"),
            login_user=dict(default="dbadmin"),
            login_password=dict(no_log=True),
        ),
        supports_check_mode=True,
    )

    if not pyodbc_found:
        module.fail_json(msg=missing_required_lib("pyodbc"), exception=PYODBC_IMP_ERR)

    role = module.params["role"]
    assigned_roles = []
    if module.params["assigned_roles"]:
        assigned_roles = module.params["assigned_roles"].split(",")
        assigned_roles = [_f for _f in assigned_roles if _f]
    state = module.params["state"]
    db = ""
    if module.params["db"]:
        db = module.params["db"]

    changed = False

    try:
        dsn = (
            "Driver=Vertica;"
            f"Server={module.params['cluster']};"
            f"Port={module.params['port']};"
            f"Database={db};"
            f"User={module.params['login_user']};"
            f"Password={module.params['login_password']};"
            f"ConnectionLoadBalance=true"
        )
        db_conn = pyodbc.connect(dsn, autocommit=True)
        cursor = db_conn.cursor()
    except Exception as e:
        module.fail_json(msg=f"Unable to connect to database: {e}.")

    try:
        role_facts = get_role_facts(cursor)
        if module.check_mode:
            changed = not check(role_facts, role, assigned_roles)
        elif state == "absent":
            try:
                changed = absent(role_facts, cursor, role, assigned_roles)
            except pyodbc.Error as e:
                module.fail_json(msg=f"{e}", exception=traceback.format_exc())
        elif state == "present":
            try:
                changed = present(role_facts, cursor, role, assigned_roles)
            except pyodbc.Error as e:
                module.fail_json(msg=f"{e}", exception=traceback.format_exc())
    except NotSupportedError as e:
        module.fail_json(msg=f"{e}", ansible_facts={"vertica_roles": role_facts})
    except CannotDropError as e:
        module.fail_json(msg=f"{e}", ansible_facts={"vertica_roles": role_facts})
    except SystemExit:
        # avoid catching this on python 2.4
        raise
    except Exception as e:
        module.fail_json(msg=f"{e}", exception=traceback.format_exc())

    module.exit_json(changed=changed, role=role, ansible_facts={"vertica_roles": role_facts})


if __name__ == "__main__":
    main()
